Developing apparatus

ABSTRACT

A developing assembly wherein a developing applicator receives electroscopic marking particles from a donor member supported in a sump housing, such housing having a resilient side wall which is flexed to reduce or prevent excessive accumulation of marking particles as a result of the donor member&#39;&#39;s rotation.

United States Patent 1191 Howell et al.

[ 1 Nov. 112, i974 1 1 DEVELOPING APPARATUS [75] Inventors: RichardStockton Howell, Webster;

Stuart Evan Hotchltiss, Williamson,

both of NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: May 20, 1970 [21] Appl. No.: 39,686

152 US. 131 222/203, 222 414, 222/9101 511 lm. c1. oos 05/70 58 Field ofSearch 222/410, 414, D10. 1, 221,

[56] g References Cited UNITED STATES PATENTS Church 222/202 3.399.6529/1968 (juwmn 222/57 X Primary Eraminer-Stanley H. Tollbcrg AssistantExaminer-John P. Shannon [57] ABSTRACT A developing assembly wherein adeveloping applicator receives electroscopic marking particles from adonor member supported in a sump housing, such housing having aresilient side wall which is flexed to reduce or prevent excessiveaccumulation of marking particles as a result of the donor membersrotation.

7 Claims, 1 Drawing Figure PATENTEUHHY 12 I974 BY RICHARD HOWELL 5. M

Al TTORNEV 1 DEVELOPING APPARATUS This invention relates generally todonor assemblies for and method of making marking particles available toa'developing applicator in an apparatus wherein a latent image, eitherelectrostatic or magnetic, is to be developed with such particles.

In conventional developing systems, a rotating cylindrical natural furbrush has'sometimes been used to convey marking particles referred tocommonly as toner, into transfer relation with the latent image to bedeveloped.

In the past, toner has been sprinkled or blown onto the brush as well asbrought into contact with the brush via a donor assembly in the form ofa solid cylindrical roller which rotates in a sump of developer, i.e.'toner and carrier bead mixture.

However, these approaches have suffered certain numeral 4. This toner isconfined by two end plates 6 and a bottom member or panel 8 and a sidewall 10.

The side wall 10 is comprised of two planar sections, oneof which isdesignated by reference numeral 11.

The other portion includes a rectangular frame 16 which is suitablyattached to flanges of portion 11 and bottom plate 8. In its attachedposition, frame 16 holds in place a flexiblemember or diaphragm 14across the opening in the sump housing between the aforemen- .tionedflanges and end plates 6. This flexible member date the donor roller 12as it rotates within the housing.

One disadvantage is the effect of pumping or the uniform and constantmovement of the developer in one direction as the donor roller movesthrough the sump. As the body of the roller moves, it pushes developerlbefore it and soon forms a cavity in the quantity of developer in thesump. Additionally, the prior art veloper to break up or fall into thiscavity to the extent that the donor assembly would allow. Suchtechniques necessitated complex apparatus within the sump housing whichtook up space normally occupied by develope'r. I

Therefore, it is an object of the present invention to improve donorassemblies for toner conveyance to a developing member.

It is another object of the present'invention to provide an improvedmethodand means for agitating toner within the sump-of a developingassembly.

These and other objects which may become apparent are accomplished inaccordance with the principles of the present invention wherein thehousing for the donor assembly has a flexible wall or portion thereofwhich is flexed in a periodic manner to push compacted using agitatorswere helpful in solving the problem but or accumulated toner away fromthe wall and into renewed contact with the donor roller.

THese objects and other features of the present invention may beappreciated and better understood upon reading the following detaileddescription in connection with the appended drawings wherein the soleFIGURE illustrates a perspective view of a donor housing with partsbroken away for simplicity to show the interior thereof.

The FIGURE shows clearly only one end of the housing. The end not shown,however, is substantially identical to the one illustrated.

The FIGURE illustrates a donor assembly housing This donor roller "alsoassists inkeeping the developer material or toner within the otherportion of the donor housing. The portion of the donor roller 12 whichis exposed to the outside of the donor housing is adapted to becontacted by rotating fibrous applicator 15, for example, shown inbroken lines during the developing cycle. The donor roller maybe'tubu'lar or solid and may be coated with an appropriate insulatingmaterial to aid in attracting in conveying toner to the developingappli-v cator. I

The donor roller may be driven to rotationby motive power applied to aninput shaft 18 which corresponds to the axis of the donor roller 1-2 andis coupled thereto.

Mountedon the shaft 18 is an actuating cam 20 which along that portionco-extensive with the elongated dimension of thedonor housing is anagitator bar 28 which is fixed to this U-shapedmember.

As motive power is supplied to input shaft 18 th donor'- roller '12 andcam 20 are caused to rotate in the direction of the arrows. Rotation ofcam 20 causes the U shaped member 22 to oscillate about a pivot point 24which may be a suitable pin or other fastener to attach the arms 22 toend plates 6 of the housing. During a portion of each oscillation ofU-shaped member 22 bar 28 presses inward on the flexible side wall ordiaphragm 14. This results in moving the quantity of toner accumulatedon this side wall into any cavities created by the donor rollersrotation and into contact with the donor roller for continued operation.

In the normal mode of operation the donor roller is I either movedcontinuously or moved in a periodic manner which results in the periodicand regular flexing of the diaphragm 14. This regular flexing maintainsthe sump of electrostatic marking particles in proper relationship withthe donor roller for good donation to a developing applicator. Whilespecific details and configuration of the donor housing of the presentinvention has been described, it

will become apparent to the person skilled in the art that the preciseconfiguration of the donor housing may be altered without parting'fromthe principles of the present invention. For example, the side wall 10instead of being made up of two non-coplanar members may lay within asingle plane. v

In addition, while an elongated cylindrical member has been shown as theagitator bar 28 it will be recognized that other shapes andconfigurations may be employed with substantially the same result. It isonly necessary to use a member which does not rupture the flexiblediaphragm wall 14. In addition, while the agitator bar 28 has beendisclosed as being only in contact with the flexible diaphragm 14 itwill be readily realized that it may be molded into the diaphragm 14 orin some manner fixed thereto so as to positively act on this memberduring its complete motion.

Also, although the oscillating member 22 and associated bar 28 aredescribed as being actuated by the donor rollers movement, it may bereadily appreciated that the flexing of diaphragm 14 may be accomplishedin other ways either as a function of the rotation of the donor rolleror not. Furthermore, while a solid cylindrical donor roller has beenused to aid the detailed description of the present invention, it shouldbe apparent that donor members of other configurations are equallysuited for use in the present invention. For example, natural fur orsynthetic fibrous brushes maybe used.

While the inventionhas been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the true spirit and scope of theinvention.

What is claimed is:

1. A developing assembly comprising:

a. a developing applicator capable of rotation about a first axis; b. adonor member having an input shaft responsive to motive power to rotatesaid donor member about a second axis substantially parallel to saidfirst axis; and, c. a sump housing adapted to contain a quantity ofmarking particles mounted about said donor mem-. ber, said sump housinghaving 1. an openingtherein to permit contact between said developingapplicator and said donor member,

2. an end plate having an aperture through which said input shaft passesand which permits-said shaft to rotate relative to said end plate,

3. a side wall attached to said end plate and having a flexible portion,and 4. means responsive to rotation of said shaft for flexing saidflexible portion.

2. A developing assembly as defined in claim 1 wherein said meansincludes a flexing member movable against said flexible portion.

3. A developing assembly as defined in claim 2 wherein said meansincludes a cam fixed to and for rotation with said input shaft andcam-following means responsive to the rotation of said cam and connectedto said flexing member for oscillating said flexing mem ber against saidflexible portion.

4. An assembly according to claim 1 wherein said donor member issupported in said sump housing closer to a wall of said housing oppositesaid side wall, and

wherein said flexing means is disposed for contacting said oppositewall.

5. A donor assembly comprising: spaced apart end plates, a bottom panelextending between said end plates and attached thereto,

aside wall attached to said bottom panel and said end plates, said sidewall having a portion thereof constituting a rubber diaphram,

means for flexing said diaphram into the volume formed by said plates,panel and wall,

a donor member rotatably supported at least partially within said volumefor contacting marking particles contained therein, and

means responsive to rotation of said donor member for effectingoperation of said flexing means.

6.'An assembly according to claim 5 wherein said responsive meanscomprises a cam and follower arrangement operatively associating saiddonor member with said flexing means.

7. A developing assembly comprising:

a developing applicator,

a sump housing for containing a quantity of marking particles,

a donor member rotatably supported in said sump housing for transportingmarking particles from said sump housing to said developer applicator,and

means responsive to rotation of said donor member for flexing one wallof said sump housing into the volume delineated by said sump housing.

1. A developing assembly comprising: a. a developing applicator capableof rotation about a first axis; b. a donor member having an input shaftresponsive to motive power to rotate said donor member about a secondaxis substantially parallel to said first axis; and, c. a sump housingadapted to contain a quantity of marking particles mounted about saiddonor member, said sump housing having
 1. an opening therein to permitcontact between said developing applicator and said donor member,
 2. anend plate having an aperture through which said input shaft passes andwhich permits said shaft to rotate relative to said end plate,
 3. a sidewall attached to said end plate and having a flexible portion, and 4.means responsive to rotation of said shaft for flexing said flexibleportion.
 2. an end plate having an aperture through which said inputshaft passes and which permits said shaft to rotate relative to said endplate,
 2. A developing assembly as defined in claim 1 wherein said meansincludes a flexing member movable against said flexible portion.
 3. aside wall attached to said end plate and having a flexible portion, and3. A developing assembly as defined in claim 2 wherein said meansincludes a cam fixed to and for rotation with said input shaft andcam-following means responsive to the rotation of said cam and connectedto said flexing member for oscillating said flexing member against saidflexible portion.
 4. An assembly according to claim 1 wherein said donormember is supported in said sump housing closer to a wall of saidhousing opposite said side wall, and wherein said flexing means isdisposed for contacting said opposite wall.
 4. means responsive torotation of said shaft for flexing said flexible portion.
 5. A donorassembly comprising: spaced apart end plates, a bottom panel extendingbetween said end plates and attached thereto, a side wall attached tosaid bottom panel and said end plates, said side wall having a portionthereof constituting a rubber diaphram, means for flexing said diaphraminto the volume formed by said plates, panel and wall, a donor memberrotatably supported at least partially within said volume for contactingmarking particles contained therein, and means responsive to rotation ofsaid donor member for effecting operation of said flexing means.
 6. Anassembly according to claim 5 wherein said responsive means comprises acam and follower arrangement operatively associating said donor memberwith said flexing means.
 7. A developing assembly comprising: adeveloping applicator, a sump housing for containing a quantity ofmarking particles, a donor member rotatably supported in said sumphousing for transporting marking particles from said sump housing tosaid developer applicator, and means responsive to rotation of saiddonor member for flexing one wall of said sump housing into the volumedelineated by said sump housing.